In recent years, with the advancements in speed-up and energy conservation of the machines, toners having excellent low-temperature fixing ability are in demand. In view of the above, as a resin binder for use in a toner, numerous studies on polyesters testing for excellent low-temperature fixing ability are made.
On the other hand, studies on those using lignin compounds using raw materials from a plant source are also made.
Patent Publication 1 discloses, as an objective of inexpensively obtaining a natural color brown and at the same time having environmental resistance and background fogging, a color toner characterized in that a compound having a phenylpropane backbone is blended.
Patent Publication 2 discloses, as an objective of having sufficient offset resistance and low-temperature fixing ability upon fusing, and also being free from generating winding around a fixing roller, a toner for electrostatic image development, characterized in that the toner contains, as a binder component, a resin obtained by subjecting lignin and cellulose to an esterification treatment or etherification treatment.
Patent Publication 3 discloses, as an objective of providing a toner for electrophotography having a very low environmental burden during production and upon discarding, without lowering image quality, characterized in that the toner contains a resin binder comprising a biodegradable polymer, a releasing agent comprising a plant-based natural wax, a colorant comprising a food pigment, and a charge control agent comprising a natural mineral.